Apple's own figures for Q1 - the company's second fiscal quarter - put total iPad shipments at 11.8m units, with 4m Mac sales, some of them desktops. Even assuming Apple sold no desktops at all - all those 4m Macs were MacBooks - that still puts Apple's total less than the figure DisplaySearch gives. DisplaySearch reckons 13.6m iPads shipped.

We've asked DisplaySearch how it accounts for the discrepancy. To be fair, the company does point out that its numbers are "preliminary", so subject to change before the final figures are posted.